#ifndef GPS
#define GPS 
struct gps
{
	double latitude;   //N  S
	char   north_south;
	double longitude;  //E W
	char east_west;
	double heading;
	double declination;
	char declination_ew;
	int  valid_flag;
	int diff_delay;
};
int gps_init(const char* port_name);
int gps_update();
int get_gps(struct gps* gps_ptr);
int get_heading_angle(double *heading);
void printf_gps(const struct gps* gps_ptr);
void dir2continuous_dir(const double continuous_heading, const double dir, double &continuous_dir);
int get_continuous_heading_angle(double &continuous_heading);
#endif /* ifndef GPS */
